For hard, unconsolidated ground and deep construction, liquefaction countermeasures are also addressed by the "sleeve injection method."

A chemical grouting method that is most effective for hard, unconsolidated ground. It is suitable for deep construction projects and can also be applied for liquefaction countermeasures.

The sleeve injection method is a double packer technique that separates the installation of injection pipes from the injection work. It is suitable for large-scale construction projects or cases where high effectiveness is required, as well as for deep construction projects, and can also be applied for liquefaction countermeasures. 【Applications】 ● Stabilization of the bottom slab and backfill of the shaft (waterproofing and strength increase) ● Protection of soil retention deficiencies ● Stabilization of the face of shield or thrusting ● Prevention of loosening in the route section of shield or thrusting ● Stabilization of the backfill and bottom slab of deep foundations (waterproofing and strength increase) ● Liquefaction countermeasures 【Features】 ● Covers almost all target ground areas. It is most effective against hard, unconsolidated ground where other methods cannot be applied. ● By using injection materials with a long gel time, low-speed and low-pressure injection is possible, allowing for reliable permeation injection even in fine sand layers. ● The external injection pipe is left underground, enabling re-injection at necessary locations even after the initial injection. ● A complete packer can be created with seal grout, completely preventing the escape of injection material from around the injection pipe. ● There is very little ground deformation, and the impact on nearby structures is also minimal.

Ground improvement